The objective of the projects in this application is to improve the therapeutic results for children with ALL. Mechanisms and efficacy of leukemia cell killing (Project 2 & 3), as well as the development of new laboratory-based therapies (Project 1) all depend on ascertaining tumor specimens from all patients at diagnosis and relapse. As a result, the clinical projects require research resources which extend beyond direct patient care and clinical laboratory functions. Without clinical research support provided in this Core, it would be impossible to coordinate the proper collection of multiple research specimens (e.g., Day 7 marrow for apoptosis studies - Project 3; serial marrow specimens for minimal residual disease studies - Project 2, and timely follow-up of patients on long-term studies of cardiac and neuropsychologic toxicity (Project 4). Equally important for the success of this project is the biostatistical collaboration with individuals in this Core who provide abstraction, computerized entry, and quality control of data, as well as assist in the design and analysis of clinical research protocols. The purpose of this Core is to provide the following services that will be utilized by all of the research projects: 1) to collect research specimens and coordinate patient follow-up at DFCI; 2) to coordinate the collection of research specimens and follow-up data from consortium centers; 3) to ensure that study parameters are followed and confirm eligibility and patient registration; 4) to ensure accuracy of submitted data from outside sources; 5) to provide biostatistical collaboration for clinical research protocols (including all aspects of the design, conduct, analysis, and reporting of the clinical protocols, and the direction of data processing and data quality control assurance); 6) to provide data management for the collection of individual patient information; 7) to provide data coordinator to maintain a computerized database, with assured quality control and standardized reporting; 8) and to provide computing resources for data processing, forms design and statistical analyses.